First of all I want to thank you for commenting on my build guide. This is my first guide so I appreciate your tips.
Vayne is low threat mainly because she uses Tumble it is easy to stun and land combinations on her.
The play Style is a forward play style. It is sort of a mix between roam style and Adc style. I designed it mainly to build lux strong and not get as many assists but get more kills.
Runes are weird because I only have two rune pages so I have a mana page and a no mana fighter page. I wasn't sure if I should post it because it wasn't specialized for lux.

for the items I'll try to explain them more in another section. Next time I edit this I'll be more specific on when to use the combos.

Thank you for reading an commenting on my build. :) I'll try to us your impute to better the my guide.

Your Build is quite questionable. There are a lot of uncommon choices and you don't even explain them further. If you would like tanky stats like mana and health, I would recommend Rod of Ages. Eye of the Watchers and Banner of Command are support items. There are better cdr items and mr items. I don't know what kind of tactic you use with those items. Are you going for a team oriented playstyle?

Combos also don't make sense. When I'm fleeing I wouldn't shield and ult unless the enemy is far away. The channel time would actually kill me. I think you should explain in-depth in what kind of situations you use your spells. Sum it up in one chapter.

Add runes and eplain all your choices. Why Deathfire Touch instead of Thunderlord's Decree ? Your masteries are also strange if you want much AP. And also why Vayne?